Portable power bank



FIG. 1 is a perspective view of a portable power bank showing my new design, showing a flexible electrical connector of the portable power bank in a stowed position;

FIG. 2 is a front elevational view of the portable power bank;

FIG. 3 is a rear elevational view of the portable power bank;

FIG. 4 is a left side elevational view of the portable power bank;

FIG. 5 is a right side elevational view of the portable power bank;

FIG. 6 is a top plan view of the portable power bank;

FIG. 7 is a bottom plan view of the portable power bank; and,

FIG. 8 is similar to FIG. 1, but showing the electrical connector of the portable power bank in an extended position and connected to an electronic device.

The broken lines of the figures are for the purpose of illustrating environment and form no part of the claimed design. 

The ornamental design for a portable power bank, as shown and described. 